IRS Scam designed to wake you up and scare the CRAP out of you. Leaves a threatening sounding voicemail designed to make you call back in an absolute panic. Started with a female, never identified herself, and notifying you that this is a courtesy call to warn you about impending arrest. Sounds of call center, rapid speech, definitely foreign accent, trying to give you no time to think. Asks for an odd amount of money, to make it more realistic, and demanding immediate payment to stop an arrest warrant. When I asked how could I know this was not some kind of scam, was transferred to a supervisor, male this time, who started to give me a spiel about it not being his job to prove who he was, and adding to the pressure. Luckily I looked up the number, and found this site that showed it was a scam. Hung up on them and they have not called back.